Plastic trash bags are produced and sold on an extensive scale in a variety of shapes and sizes. The vast majority of these bags are made of polyethylene film. The bags in general include sidewalls that are often joined by one or more seams, a closed lower bottom end, and an open top end. The trash bag can serve as a liner for a trashcan. Conventionally, an upper edge of the bag, which defines the opening, is rolled over an upper lip of the trashcan to position the bag in an open position and to secure the bag to the trashcan. It can be difficult to maintain the bag in the open position and in a secured relationship with respect to the top of the trashcan when the bag is loaded with trash.
The use of elastic means for securing the open end of a liner bag to the top edge of a trashcan is generally known. It is desirable for such an elastic top bag to provide adequate “grip” to the trashcan to prevent the bag from falling into the trashcan when loaded with trash. One problem encountered with producing such trash bags involves the interaction between the elastic material and the film substrate of the bag. For instance, the elastic material must be able to stretch and contract to provide the desired “grip” but the film substrate is typically inelastic.
An attachment method used in the incontinence industry involves the intermittent bonding or “stitch attachment” of elastic material onto a substrate such that between every two bond regions there is a discernable unattached length of the heat activated elastic film material. This type of basic pattern can be repeated to make spaced intervals or “stitches” of attached and unattached sections. Once the garment has been processed, the unattached portions of the elastic material shrink to provide a shirred and elastic garment. This attachment method can also be applied to making elastic top trash bags, such as shown in U.S. Pat. No. 5,120,138 to Midgley and International PCT Patent Application No. WO 00/39005 to Marchal
There is a need in the art for an improved method of continuous production of elasticized liner bags which is cost effective.